This is how mother nature does her negative feed back loops, no one or nothing gets to dominate, unfortunately species com and go. We human might happens to be just one, if we still choose to live the way we use to be.

Over population will definitely be one of the major factors that push us to end ourselves. Either through intraspecies warfares or over exploiting the planet and release some deadly new pathogens.

Hope we realise that in time =]